Answer:
The third response
Step-by-step explanation:
Given :
Two equations :
-8x + 3y = -17 ....1)
3x - y = 7 ....2)
To Find :
The solution of the system.
Solution :
Multiplying equation 2) by 3 and adding with equation 1), we get :
(-8x + 3y) + 3(3x - y) = -17 + 21
x = 4
Putting above value of x equation 2) we get :
12 - y = 7
y = 5
Therefore, solution of system is ( 4,5 ).
Answer:
Quantity of heat needed (Q) = 722.753 × 10³
Step-by-step explanation:
According to question,
Mass of water (m) = 40 kg
Change in temperature ( ΔT) = 18°c
specific heat capacity of water = 4200 j kg^-1 k^-1
The specific heat capacity is the amount of heat required to change the temperature of 1 kg of substance to 1 degree celcius or 1 kelvin .
So, Heat (Q) = m×s×ΔT
Or, Q = 40 kg × 4200 × 18
or, Q = 3024 × 10³ joule
Hence, Quantity of heat needed (Q) = 3024 × 10³ joule
In calories 4.184 joule = 1 calorie
So, 3024 × 10³ joule = 722.753 × 10³
It’s 6x6=36, because if 4 over 2 was 4 twice then 6 over 2 is 6 twice.
